1. Field of the Invention
The present invention relates electrical connectors and more particularly to an electrical signal connector consisting of a metal locknut, a core tube, an elastic cylindrical casing and a barrel for quick connection with a coaxial cable by means of moving the barrel relative to the cylindrical casing to deform the cylindrical casing without causing damage to the coaxial cable.
2. Description of the Related Art
Following fast development of electronic and multimedia technology, advanced TV, audio system, video player, digital camera, video game machine and may other electronic products have been continuously created to serve people. Due to critical requirements from consumers, signal transmission requires high stability and rapid speed. To achieve high performance, high quality audio and video equipment must be used with high quality signal lines and signal connectors.
Subject to the application of telephone technology, video technology and internet technology, global communication becomes faster and cheaper. Transmission of video signal through a cable assures signal stability and reliability. Therefore, CATV (closed-circuit TV) is developed after the application of wireless TV and satellite TV. A CATV is adapted for providing television programs to consumers via RF signals transmitted to televisions through coaxial cables or digital light pulses through fixed optical fibers located on the subscriber's unit. Establishing a closed-circuit television system requires installation of cables between the provider and the subscribers. When a cable is extended to a house, an electrical signal connector must be used to connect the cable to an indoor electric or electronic device. During installation, the size, specification and impedance (for example, 75 Ohm) of the connector must match with the cable. After insertion of the cable into the connector, a crimping tool shall be used to crimp the connector, enhancing connection stability and protecting the connection against external water or impurities.
FIGS. 12 and 13 illustrate a conventional electrical signal connector A for this purpose. As illustrated, the electrical signal connector A comprises a locknut A1, an outer tubular member A3 connected to the locknut A, an inner tubular member A2 mounted in the outer tubular member A3, a barrel A4 slidably coupled to the outer tubular member A3. During installation, the center conductor B1, inner dielectric insulator B2 and aluminum foil shield B3 of the coaxial cable B are inserted into the outer tubular member A3 and then into the axial hole A20 of the inner tubular member A2 to have the braided metal wrapper (woven copper shield) B4 and outer plastic sheath B5 of the coaxial cable B be sleeved onto the inner tubular member A2 within the outer tubular member A3, and then a crimping tool is operated to move the barrel A4 relative to the outer tubular member A3 and to compress outer tubular member A3 and to force a barbed portion A31 of the outer tubular member A3 into engagement with the braided metal wrapper (woven copper shield) B4 and outer plastic sheath B5 of the coaxial cable B against the inner tubular member A2. Thus, the electrical signal connector A and the coaxial cable B are fixedly fastened together. According to this design, the barrel A4 has simply a part of the inner wall kept in contact with the outer tubular member A3. When moving the barrel A4 relative to the outer tubular member A3, the outer tubular member A3 may be biased relative to the coaxial cable B, and the barbed portion A31 of the outer tubular member A3 may be not positively forced into engagement with the braided metal wrapper (woven copper shield) B4 and outer plastic sheath B5 of the coaxial cable B against the inner tubular member A2.
Further, it is necessary to insert the coaxial cable B trough the barrel A4 before inserting the coaxial cable B into the axial hole A20 of the inner tubular member A2. After insertion of the center conductor B1, inner dielectric insulator B2 and aluminum foil shield B3 of the coaxial cable B into the axial hole A20 of the inner tubular member A2, the barrel A4 can then be attached to the outer tubular member A3 and then moved relative to the outer tubular member A3 and to compress outer tubular member A3 and to force a barbed portion A31 of the outer tubular member A3 into engagement with the braided metal wrapper (woven copper shield) B4 and outer plastic sheath B5 of the coaxial cable B against the inner tubular member A2. This installation procedure is complicated, requiring much effort. Further, if the outer tubular member A3 is biased relative to the coaxial cable B and the barbed portion A31 of the outer tubular member A3 is not positively forced into engagement with the braided metal wrapper (woven copper shield) B4 and outer plastic sheath B5 of the coaxial cable B against the inner tubular member A2, the signal transmission quality will be affected.
Therefore, it is desirable to provide an electrical signal connector, which eliminates the aforesaid drawbacks and facilitates quick and accurate installation, assuring a high level of signal transmission quality.